Health Calculators Calculators
Five free tools for everyday health screening and planning — from body weight classification to daily hydration needs. Built for quick, private, on-device calculations.
Health calculators are most useful as a starting point for a conversation with a doctor or trainer, not a replacement for one. These five tools use formulas referenced from major health bodies like the WHO, CDC, and NIH, so the numbers you get are grounded in recognized standards.
❤️ All Health Calculators
🧭 Which Health Calculator Should You Use?
Checking your weight category
The BMI Calculator gives a quick screening classification using WHO standard ranges.
Planning weight loss or gain
The Calorie Calculator estimates your TDEE (daily energy burn) using the Mifflin-St Jeor formula.
Staying hydrated
The Water Intake Calculator adjusts your daily target for body weight, activity level, and climate.
Tracking a pregnancy
The Pregnancy Calculator estimates your due date and current trimester from your last period or conception date.
Fixing your sleep schedule
The Sleep Calculator finds ideal bed/wake times based on 90-minute sleep cycles.
❓ Frequently Asked Questions
❓ Can these calculators replace a doctor's advice?
No. These tools are for general screening and education only. For any medical decision, talk to a qualified healthcare professional.
❓ Is BMI accurate for athletes?
Not always — BMI can't distinguish muscle from fat, so athletes with high muscle mass often score as 'overweight' despite low body fat. See the BMI Calculator's guide for details.
❓ Where do the formulas come from?
Each calculator lists its references at the bottom of the page, including sources like WHO, CDC, and NIH.